AVR-Chat

Roy E. Burrage wrote:
> There's also a "depletion" mode device that's normally on, turned off, 
> much like a standard JFET device.  These were actually called Insulated 
> Gate Field Effect Transistors (IGFET) back in the old days.  I don't 
> know that these devices are available except as small signal devices, or 
> if they're even available at all any more.  It's been a while since I 
> needed to use a depletion type.  There is no Source-Drain body diode in 
> this type device and I believe the last time I did, it was because the 
> Source-Drain diode was problematic in that application.

Supertex makes a few.  Mainly, I think,  for use in HV linear supplies.

> Power MOSFETs do make very inexpensive, high current diodes.  Has anyone 
> ever experimented with them with respect to current sharing in parallel 
> device configurations, as diodes, like we would when using them in 
> parallel as MOSFETs?

Yes, and not surprisingly they have the same issues.  The one attempt I 
observed using them purely as diodes in parallel failed for the obvious 
reason.

I have used them successfully in parallel when they were also in 
parallel with an 'on' MOSFET.

Robert
-- 
http://www.aeolusdevelopment.com/

  From the Divided by a Common Language File (Edited to protect the guilty)
ME - "I'd like to get Price and delivery for connector Part # XXXXX"
Dist./Rep - "$X.XX Lead time 37 days"
ME - "Anything we can do about lead time?  37 days seems a bit high."
Dist./Rep - "that is the lead time given because our stock is live....
we currently have stock."